BL 9 Flashcards
Whats the name of the tongue?
Lingula
What are the two functions of salava?
To wet the food
Break down the food
What are the four layers of the gut wall?
Mucosa
Submucosa
External muscle layers
SEROSA
Whats the name of the first layer that lining of the gut?
Mucosa
- Epithelium
- Lamina Propria
- Muscularise mucosae
What are the three layers of the mucosa
- Epithelium
- Lamina Propria
- Muscularise mucosae
Name a function of the sub mucosa?
Secretion from glands
Name a structure of the sub mucosa?
a layer of connective tissue bearing: glands, arteries, veins nerves
The muscular layer of the gut wall can be broken down into two types of muscle?
Inner - circular muscle
Outer - Longitudinal muscle
What are the enzymes in salava?
Amylase (carbs) and Lipase (fats)
Does the upper oesophagus have voluntary or involuntary control?
Voluntary
Does the lower oesophagus have voluntary or involuntary control?
involuntary
What are the two nerve plexi in the oesophagus?
Myenteric plexus
Submucosal plexus
What type of epithelium is osophagus?
Stratified squamous (non-keratinised)
What are Parietal cells?
Parietal cells secrete H+
ions into the lumen and HCO3 ions into nearby capillaries, which move it
to surface mucous cells.
What are Enteroendocrine cells?
include G cells which secrete gastrin. The wider gastric mucosa responds to this hormone by secreting acid.
What are Chief cells?
secrete pepsinogens
which are converted into pepsins which partly hydrolyse proteins. Found at the base of the pit
What three things are secreted into the dodenum
Chyme from stomach
Bile from Gall bladder (store)
Pancreatic Juices
Where is bile made?
Made in the liver
Stored in the gall bladder
Function of duodenum?
Think of what is secreted by where and its effect (4)
1) Water drawn in(chyme becomes isotonic)
2) Secretion of Bile (neutralisation and emulification)
3) Pancreatic juices (neutralise and digestive enzymes)
4) Absorption of Iron
The enzymes from the pancreas have 4 functions…
Cleave peptides to amino acids
Cleave polysaccharides to monosaccharides
Break down and re-form lipids
Break down nucleic acids
How long is the small intestine (fun fact lol)
22 ft (7meters) tennis court surface area
Where do sugars get absorbed?
Mostly in Jejunum
Where do amino acids get absorbed?
Mostly in Jejunum
Where do fatty acids get absorbed?
Mostly in Jejunum
Where does Vit B12 get absorbed?
Ileum
Where does bile acids get absorbed?
Ileum
What type of epithelium is found in the crypts of the large intestine?
Simple columnar epithelium
How long does water recovery take in the large bowel?
20 hours
Name one process that uses the gut bacteria to function
synthesis of vitamins K, B12, thiamine and riboflavine
• breakdown of 10 to 20 bile acids
• conversion of bilirubin to non-pigmented metabolites
- (all readily absorbed)
What are the types of neural control in the gut.
Somatic (mouth and first ⅓ of oesophagus, last sphincter of anus)
Post ganglionic neurones form plexuses
- one between muscle layers of gut wall
- one between submucosa and muscularis externa
What does secretin do?
promotes (bicarbonate) secretion from duct cells
of pancreas
What does Cholecystokinin (CCK) do?
synthesised and secreted by enteroendocrine cells of the
duodenum
1. promotes release of digestive enzymes from the pancreas
2. promotes release of bile from gall bladder (stimulates it to contract)
3. is a hunger supressant
Three main blood vessel of the liver. Name and explain.
Portal Vein - Nutrient rich vein going to the liver
Proper Hepatic Artery - O2 rich artery going to liver
Hepatic Vein - Leaving liver
What does catabolic mean?
breaking down reactions
What does anabolic mean?
Building reactions
What are the two capillary systems in series, in a human body?
1) Hepatic-Portal System
2) Hypothalamo-hypophyseal portal system
Hepatic-Portal System. If you imaginw it. How many capillary beds are there? Where are these? What is the name of the vein between them?
2 Capillary Beds
Stomach and Intestine
Liver
Hepatic Portal Vein
Function of the liver. 5
Metabolism (anabolic and Catabolic) Storage - Carbs and Fats Production of Bile Detoxification Protein Metabolism
Why is ammonia dangerous?
It can cross the blood-brain barrier.
The liver can convert this to urea
What doesnt travel in the portal vein?
Lipids
Fat soluble Vits ADEK
What does the Liver store?
Iron Vit A B12 D K Glycogen
Anabolism in the liver examples.. 2/4
Albumin
Glycogen
Numerous coagulation factors
Haematopoiesis in fetus
Catabolism/breakdown/toxin degredation in the liver examples..? 3/5
Drugs (cytochrome P450) Hormones Haemoglobin Poisons (cytochrome P450) Can take over removal of aged red cells after splenectomy
Whats the livers exocrine function
Bile excretion
Name something the liver produces. 1
Angiotensinogen
Thrombopoetin
Insulin like growth factor 1 (IGF-1)
What is the livers endocrine function?
• It produces Angiotensinogen Thrombopoetin IGF-1 • It modifies to active forms Vitamin D Thyroxine • It breaks down Insulin Glucagon Oestrogen and progesterone
Whats characteristics of liver cells (histologically)
Lots of Mitochondria
Lots of Peroxisomes
Lots of RER
Lots of RIbosomes
Blood to the liver?
Portal Vein (75%) Proper Hepatic Artery (25%)
Whats a sinusoid?
Irregular tubular space for the passage of blood, taking the place of capillaries and venules in the liver, spleen and bone marrow
How many sides does a Liver lobule have?
Which direction does the blood flow?
6
Towards the centre
Kupffer cells
Kupffer cells are monocyte derived specialist macrophages that form
part of the lining of the sinusoids
Stellate Cells
Stellate cells are full of cytoplasmic vacuoles containing Vitamin
A. A source of vitamin A
What are the roles of bile?
Neutralisation
Emulsification
